Geographic distribution of prostate cancer incidence in the era of PSA testing, Connecticut, 1984 to 1998.

To evaluate the geographic variation of prostate cancer incidence in Connecticut during a 15-year period: before the introduction of prostate-specific antigen (PSA) testing (1984 to 1988), during its introduction (1989 to 1993), and after its widespread adoption (1994 to 1998). A spatial scan statistic was used to detect and test the significance of the geographic rate variation among 29,944 incident cases. During 1984 to 1988, eight locations had incidence rates that differed significantly from the statewide level; for 1989 to 1993, only two locations were identified. By 1994 to 1998, a significant rate variation was noted for 10 locations around Connecticut. The observed geographic variation of incidence rates may reflect differing opportunities to uncover latent cases at given locales.